The economy of South Africa is a mixed economy, emerging market, and upper-middle-income economy, one of only eight such countries in Africa. The economy is the most industrialized, technologically advanced, and diversified economy in Africa. Following 1996, at the end of over twelve years of international sanctions, South Africa's nominal gross domestic product (GDP) almost tripled to a peak of US$416 billion in 2011. In the same period, foreign exchange reserves increased from US$3 billion to nearly US$50 billion, creating a diversified economy with a growing and sizable middle class, within two decades of ending apartheid.